I think this book may be helpful for you: Aoki, Eiichi; Imashiro, Matsuhide; et al. (2000). A History of Japanese Railways, 1872–1999. Tokyo: East Japan Railway Culture Foundation. There's a couple of chapters related to the Taisho Era (1912-26). I had to research this briefly once for a class, and it appears that there is more information available for transportation initiatives during the Meiji Restoration.